1. Field of the Invention
The present invention relates to an image display apparatus and a method of correcting chroma wrinkles, and more particularly, to an image display apparatus which detects chroma wrinkles existing in blocks and corrects the chroma wrinkles by adjusting the pixel values of the blocks, and a method of chroma wrinkles correction thereof.
2. Description of the Related Art
An image display apparatus operates to process incoming video signals and display the signals through a screen, and typical examples of the image display apparatus include televisions, and computer monitors.
The image display apparatus generally uses standard compression of MPEG, H.263 based on the discrete cosine transform (DCT). The DCT converts the image signal, being represented by the luminance and color difference, into frequency region of a space and then un-converts the frequency region.
The DCT algorithm uses (n×n) pixels, called as ‘blocks’, as its basic unit. That is, one screen is partitioned into a plurality of blocks and DCT coefficients are obtained by repeating the DCT algorithm with each of the blocks. The decoder recovers the DCT coefficients being received from the encoder into original pixel values.
Interlace scanning, which is one of the scanning methods used in the image display apparatus, divides one image frame into two fields and alternately indicates through the screen in a sequence to display one image. These two divided fields are generally called top and bottom fields, upper and lower fields, or odd and even fields.
In the image display apparatus using interlace scanning, color distortion is generated during recovery of compressed image, if luminance between two fields changes abruptly or motion changes too dynamically. Such color distortion usually includes color variation from original color in certain local areas, or repeated wrinkles on the screen.
However, a conventional image display apparatus directly enters into image post-processing and does not correct the color distortion when it occurs. As a result, it is difficult to recover the original image.